The use of coaxial cable for video and data transfer is rapidly increasing. Such cables typically include a center, inner conductor surrounded by a low dielectric constant plastic foam. An outer conductor is typically bonded to the outer surface of and thereby contains the dielectric. The outer conductor may comprise a sheath of fine braided metallic strands, a metallic foil, or multiple layer combinations of either or both. A protective insulating jacket, or sheath surrounds the outer conductor and helps prevent moisture from degrading the signal path. The ends of such coaxial cables must be connected to junction boxes, amplifiers, coaxial ports and the like and coaxial connectors are well known for terminating the ends of coaxial cables.
In order to properly transmit an electrical signal, a coaxial connector should ensure that a reliable electrical connection is achieved between the outer body of the connector and the outer conductor of the coaxial cable. Likewise, a suitable coaxial connector must achieve a reliable electrical connection between the conductive pin of the connector and the center conductor of the coaxial cable. In addition, reliable coaxial connectors must form a secure mechanical connection to the end of the coaxial cable, since mechanical separation of the connector from the end of the cable will interfere with successful transmission of the desired electrical signal.
Before attaching the end of a coaxial cable to a connector, the end of the coaxial cable must be prepared. This is typically done by cutting the dielectric and the outer conductor of the cable for a short distance to expose a short segment of the center conductor. The braided metallic strands of the outer conductor may be folded over the jacket while the conductive foil remains bonded to the dielectric.
Once the coaxial cable is prepared, the prepared end is inserted into the connector until the dielectric material and conductive foil engages the insulator and the center conductor engages the conductive pin. Previous insulators typically only have a shoulder or an inner chamfer where the dielectric material and conductive foil meets the insulator. In these types of insulators, the conductive foil can become diverted inwardly toward the center conductor during installation. When the conductive foil is diverted inwardly towards the center conductor, it can affect the impedance matching of the connector or cause a signal short if the conductive foil contacts the center conductor. This in turn affects performance parameters, such as return loss or a failure to transmit the desired electrical signal.
It would be a great advantage to provide an insulator for coaxial cable connectors that overcomes the above problems and disadvantages.